Crankset for my 6'6" friend.

I have a friend that has just been bitten by the trail bug. He and I have been riding almost every weekend for the past month here on the local Oklahoma City trails. He is currently on an XL (22") Trek frame 26er. He took his bike to a local shop where he was told he would feel much better with an XL crankset. As I understand it is the length of the crank arm that is the only difference, is that the case? Also, have any of you taller riders had good or bad experiences with longer cranks? I would like to be able to tell him what is good and what to steer away from. Thanks for the help!

Celebrate a good ride by enjoying a great cigar! ..... Just not at the same time.

I have a friend that has just been bitten by the trail bug. He and I have been riding almost every weekend for the past month here on the local Oklahoma City trails. He is currently on an XL (22") Trek frame 26er. He took his bike to a local shop where he was told he would feel much better with an XL crankset. As I understand it is the length of the crank arm that is the only difference, is that the case? Also, have any of you taller riders had good or bad experiences with longer cranks? I would like to be able to tell him what is good and what to steer away from. Thanks for the help!

As a former road rider, who made the switch from 170 to 175 and noted an immediate difference, I would suggest that changing to a larger crank would be a good option, but like others have said, it can be cost prohibitive. I would suggest keeping it in mind as an option when or if you would need to replace the crank for other reasons. Long story short, I'm looking for a set of 180's myself and will try picking a set off of eBay.